Di-electrons from eta meson Dalitz decay in proton-proton collisions

The reaction pp to pp eta to pp gamma e^+ e^- is discussed within a covariant effective meson-nucleon theory.
The model is adjusted to data of the subreaction pp to pp eta.
Our focus is on di-electrons from Dalitz decays of eta mesons, eta to gamma gamma^* to gamma e^+e^-, and the role of the corresponding transition form factor F_{eta gamma gamma^*}.
Numerical results are presented for the intermediate energy kinematics of HADES experiments.